Software Learns to
Recognise Spring Thaw
(13 July 2005) Spring thaw in
the Northern Hemisphere was monitored by a new set of eyes this year - an
Earth-orbiting NASA spacecraft carrying a new version of software trained to
recognise and distinguish snow, ice, and water from space.
Using this software, the Space Technology 6 Autonomous
Sciencecraft Experiment autonomously tracked changes in the cryosphere, the
section of Earth that is frozen, and relayed the information and images back to
scientists.
The software, developed by engineers at NASA's Jet
Propulsion Laboratory, Pasadena, Calif., controls the Earth Observing-1
spacecraft. NASA's Goddard Space Flight Center, Greenbelt, Md, manages the
satellite. The software has taken more than 1,500 images of frozen lakes in
Minnesota, Wisconsin, Quebec, Tibet and the Italian Alps, along with sea ice in
Arctic and Antarctic bays.
While other spacecraft only capture images
when they receive explicit commands to do so, for the last year Earth
Observing-1 has been making its own decisions. Based on general guidelines from
scientists, the spacecraft automatically tracks events such as volcano
eruptions, floods and ice formation. The most recent software upgrade allows
the spacecraft to accurately recognise cryosphere changes such as ice
melting.
Previously, scientists spent several months developing
software for Earth Observing-1 to detect changes in snow, water and ice. The
new software is capable of learning by itself, and it took only a few hours for
scientists to train it to recognise cryosphere changes. In fact, the new
software has learned to classify the images so well that scientists plan to use
it for the remainder of the mission.
"This new software is capable of
a rudimentary form of learning, much the way a child learns the names of new
objects," said Dominic Mazzoni, the JPL computer scientist who developed the
software. "Instead of programming the software using a complicated series of
commands and mathematical equations, scientists play the role of a teacher,
repeatedly showing the computer different images and giving feedback until it
has correctly learned to tell them apart."
On Earth Observing-1, the
software searches for specific cryospheric events and reprograms the spacecraft
to capture additional images of the event.
"The software has exceeded
all of our expectations," said Dr. Steve Chien, JPL principal investigator for
the Autonomous Sciencecraft Experiment. "We have demonstrated that a spacecraft
can operate autonomously, and the software has taken literally hundreds of
images without ground intervention."
Similar software has been used to
distinguish between different types of clouds in images captured by JPL's
Multi-angle Imaging SpectroRadiometer, an instrument on NASA's Terra
spacecraft. Automatically identifying types of clouds from space will help
scientists better understand Earth's global energy balance and predict future
climate trends.
Future versions of the software also might be used to
track dust storms on Mars, search for ice volcanoes on Jupiter’s moon
Europa, and monitor activity on Jupiter's volcanically active moon Io. NASA's
New Millennium Program developed both the satellite and the software. The
program is responsible for testing new technologies in space.
(source:
NASA)